Process for making a trim strip for automobile bodies

ABSTRACT

An elongate trim strip comprising an elongate moulding, said moulding having a flat surface for receiving adhesive or otherwise attaching the strip to the body of a vehicle, a longitudinal channel formed in said moulding, a decorative surface in said channel and a weather-resistant and impact-resistant plastic overlay having radiused edges which provides a lens effect to the decorative surface beneath. Also a trim strip consisting essentially of an elongate decorative foil member having an upper surface and a lower surface and sharply defined peripheral edges, said upper surface having thereon a weather-resistant and impact-resistant overlay having radiused edges and providing a lens effect to said foil member, said overlay being formed by overcoating said upper surface of said foil member with a fluent clear plastic material which flows to said sharply defined peripheral edges and forms a positive meniscus and curing said plastic material.

BACKGROUND OF THE INVENTION

The present invention relates to an elongate strip or moulding of thetype attached to an automobile body side or other motor vehicles forprotection or decoration.

Trim strips of various configurations have been used in the automotiveindustry to decorate and protect the surfaces of an automobile,especially the body side surfaces. In recent years, emphasis has beenplaced on replacing chromed metallic moulding strips with improvedplastic trim strips which do not corrode and can be adhesively attachedto the automobile body without fasteners. There are a number of examplesof such trim strips in the patent literature.

Madonia, U.S. Pat. No. 4,206,155 (1981) discloses a decorative body sidemoulding in which a decorative strip is laminated to an extruded stripof a pliable material and the two strips are overcoated with a weatherresistant coating of acrylic monomer.

Narita, U.S. Pat. No. 4,220,681 (1980) teaches a trim in which a thinmetal layer is laminated to a plastic substrate and coated with a softPVC resin provided with a matt surface.

Wenrick, U.S. Pat. No. 4,010,297 (1977) discloses a composite trim stripmade up of two adhesively bonded non-coextensive longitudinal bodyportions, one body portion being wider than and adapted to receive theother body portion. The body portions are assembled and attached to theside of an automobile using elastomeric adhesives which serve todistribute impact.

Sawa et al, U.S. Pat. No. 3,914,482 (1975) illustrates a mouldingwherein a reflective layer is deposited on a rigid synthetic resin basewhich is coated with a clear synthetic resin layer and overcoated with aprotective layer of synthetic resin of uniform thickness.

Kent, U.S. Pat. No. 3,843,425 (1974) relates to a decorative trim havinga longitudinal passage therethrough which is filled or coated with adecorative material such as a paint. The trim is formed with a shallowchannel on its underlying surface which carries adhesive.

SUMMARY OF THE INVENTION

It is the principal object of the present invention to provide a trimstrip for use on motor vehicles which is readily manufacturable on acontinuous basis and which provides enhanced decorative effects whichcan be varied without altering the basic manufacture of the trim. Forexample by changing the decorative surface the trim can be modified tocomplement the color or style of a number of vehicles without otherwiseaffecting the manufacturing operations.

Another object of the present invention is to provide a trim strip whichis decorative, weather-resistant and which can absorb impacts.

Still another object of the present invention is a decorative trim stripwhich provides a lens effect which enhances the appearance of the trim.

The above and other objects are attained in accordance with the presentinvention which provides a trim strip for vehicle bodies comprising anelonagate moulding having a flat underlying surface for receivingadhesive or otherwise attaching the trim strip to a vehicle, an elongatechannel formed longitudinally in the moulding of the strip, a decorativesurface in the channel, and a deposit of cast plastic which overcoatsthe foil member and when cured provides an impact-resistant andweather-resistant cap having radiused edges which provides a lens effectto the decorative surface beneath. When viewed through the cast/curedplastic, the decorative surface is optically modified to enhance theappearance of the decoration. The backside of the moulding may be coatedwith an adhesive for attaching the strip to the vehicle body.

The elongate moulding portion of the trim strip is preferably formedfrom an extrudable plastic material which hardens to an impact resistantbase. The trim strip can thus be manufactured by a process whichcomprises extruding the moulding, painting a decoration or laying adecorative foil member to form a decorative surface, in a channelextrusion-formed in the moulding and thereafter casting plastic into thechannel which thereby forms a positive meniscus and hardens to a tough,weather-resistant, and impact-resistant cap having radiused edges. Theplastic cap is preferably formed from a clear plastic material. Thecurvature of the edges provides a lens effect which optically enhancesthe appearance of the decorative surface viewed through the plastic cap.A preferred plastic is a polyurethane having high impact resistance andmore preferably a flexible polyurethane which cures to a Shore Dhardness of about 45 to 65.

In another embodiment of the invention, the trim strip is manufacturedwithout a moulding and consists essentially of an elongate decorativefoil member having an upper surface and a lower surface and sharplydefined peripheral edges, said upper surface having thereon aweather-resistant and impact-resistant overlay having radiused edges andproviding a lens effect to said foil member, said overlay being formedby overcoating said upper surface of said foil member with a fluentclear plastic material which flows to said sharply defined peripheraledges and forms a positive meniscus and curing said plastic material,and preferably a layer of a pressure-sensitive adhesive on the lowersurface of said foil member for securing said trim strip to a bodysurface. Again, the preferred plastic cap is an abrasion-resistant,weather-resistant polyurethane having a Shore D of about 45 to 65 andmore preferably 45 to 55.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view and lateral cross-section of a trim stripfor a motor vehicle body in accordance with the present invention.

FIG. 2 is a lateral cross-sectional view of a trim strip in accordancewith another embodiment of the invention.

FIG. 3 is a lateral cross-sectional view of still another embodiment ofthe invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

With reference to FIG. 1, the trim strip of the present invention isgenerally indicated by the reference numeral 10. The trim strip 10comprises an elongate moulding 12 which is preferably a heat and impactresistant plastic such as acrylonitril-butadiene-styrene terpolymer(ABS), polyvinyl chloride(PVC), nylon (polyamide), polycarbonate,acrylonitril-styrene copolymer, etc. Of these, PVC is most often used asthe body portion.

Moulding 12 is preferably formed by extrusion of one of the aforesaidplastics with a channel 14 extrusion formed therein, but other processessuch as injection molding may also be used to form an elongate bodyportion having a channel therein. In FIG. 1, the channel is shown ashaving a rectangular cross-section, but other cross-sections can be usedto provide different optical effects. Channel 14 comprises a floor 16and side walls or shoulders 18 for retaining cast plastic as describedlater.

A decorative surface 20, which may be a decorative foil member, islocated in the channel 14. The term "foil member" as used hereinincludes metal foils, plastic foils (e.g. Mylar), metallized plasticfoils and paper-backed foils. The foil member may take various forms,for example, it may be a strip of metal foil which may be embossed toprovide a visual effect. Otherwise, the foil member may be a plasticfoil strip which is printed or silk-screened with a decorative design,painted or tinted. An adhesive may be used to bond the foil member tothe floor 16 of channel 14 when it is very thin and does not readily lieflat.

Alternatively, decorative surface 20 may be a painted layer or silkscreen printing layer or a decorative material otherwise depositeddirectly onto the floor 16 of channel 14. The decorative surface maythus be a solid color, a variety of colors or colored designs, or maycontain graphics along with or in place of the color or colors used.

The depth and width of the channel 14 are not particularly critical,although, the optical effect created by the cap varies with the size,shape and dimensions of the channel when the trim is manufactured bycasting plastic directly into the channel. Thus, the channel design canbe coordinated with the style of inlay to produce the desired decorativeeffect. The decorative surface 20 is overcoated with a deposit of castplastic 22. The cast plastic 22 is such that it forms a positivemeniscus in channel 14 which provides a trim having radiused edges whichprovides a lens effect for example by enhancing the decorative surface20 when viewed from above or at an angle to the trim strip 10.

For use as automobile side body trim, the cast plastic is preferably athermosetting material which is weather-resistant and does not yellow orcloud as a result of prolonged exposure to sunlight and which withstandsstrong detergents. The cast plastic should also be resistant to abrasionand impact. A number of plastics can be used for this purpose, but onewhich is particularly advantageous because it satisfies all the aboveneeds is an impact-resistant polyurethane. One polyurethane useful inthe present invention is the reaction product of polypropylene glycoland an aliphatic diisocyanate. Other plastics, such as acrylics and andepoxies may also be used. In one embodiment, a relatively soft,flexible, weather-resistant polyurethane generally characterized by aShore D hardness in the range of 45 to 65 and preferably 45 to 55 isused. Such materials are known and various ones can be used in theinvention. One that is particularly useful is the reaction product of(A) a mixture of a polyester glycol and low to medium molecular weightpolypropylenetriols and (B) an aliphatic diisocyanate-polypropylenetrioladduct.

The plastic composition 22 is cured or otherwise hardened to form theoverlay. The plastic composition is preferably cured by heating orultraviolet radiation, however, depending on the plastic used othermeans such as R. F. heating and air drying may be used to harden thecap.

The trim strip 10 may be secured to a vehicle body, such as the sidebody of an automobile with an adhesive composition 24 on the base of thestrip. Prior to installation the adhesive is protected with a releasepaper or film 26 such as wax paper or silicone release paper. Variousadhesives can be used, in the present invention. Preferred adhesives arepressure sensitive adhesives.

Alternatively, the trim strip 10 may be secured to a vehicle body byother attachment means (not shown) such as clips which are attached tothe vehicle body or use of studs which are pressure fit into openings inthe vehicle body. Other attachment means are also known in the industry.

The trim strip shown in FIG. 1 is typically manufactured by extrusionmolding the moulding 12, painting a decoration or laying a decorativefoil member to form a decorative surface in the channel formed in themoulding and casting and thereafter hardening the plastic deposit. Thedecorative surface is retained in the channel by the cast plastic whichcontacts the side walls of the channel and thereby encapsulates the foilmember. When a very thin foil member is used as the decorative surface,an adhesive may be necessary on the back of the foil to hold the foil ina flat condition in the channel during casting.

In the case of a polyurethane plastic material, the reactive components(i.e., the polyol component and the diisocyanate component) aretypically mixed at a mixing head and the mixture is cast into thechannel as it reacts. Thereafter, the cast plastic is hardened.Depending on the nature of the plastic composition forming the cap,hardening may occur upon heating or irradiation, for example, withultraviolet radiation. In the preferred case, these procedures arecarried out on a continuous basis wherein the body portion is extrudedand downstream after the body portion has set, the decorative surface isplaced in the channel and the plastic is cast and cured.

The underlying surface of moulding 12 may be coated with adhesive and arelease paper or film applied before or after the foil member ispositioned and the plastic is cast into place. The adhesive may becoated directly on the trim strip or coated on the release paper whichis thereafter applied to the trim strip.

FIG. 2 illustrates a further embodiment of the invention wherein thetrim strip is formed without an extrudable plastic moulding as inFIG. 1. As shown in FIG. 2, in accordance with one embodiment of theinvention, trim strip 27 consists essentially of a decorated and usuallyembossed foil member 30 which carries on the decorated or graphicsurface thereof a clear, plastic overlay 28 having radiused edges. Thetrim strip in accordance with this embodiment is usually equipped with alayer of adhesive 32 (generally pressure-sensitive) which is accessed byremoving a release liner 34. Trim strip as shown in FIG. 2 can bemanufactured by pre-printing and embossing an adhesive backed foilmember provided with a release liner which is kiss-cut in registry withthe printed design. By removing the selvage from around the trim andcasting a fluid plastic such as polyurethane on the trim strip, anoverlay having radiused edges which provides a lens effect is obtainedas the plastic flows to the cut edge of the foil member, stops and formsa positive meniscus. Thereafter, the overlay is cured. It isparticularly advantageous to form the overlay 28 in FIG. 2 of a soft,flexible polyurethane as the trim can be rolled up and supplied directlyto the automobile owner as part of a customizing kit. With the flexibleoverlay, the trim strip conforms to the curvature of the automobilebody.

The trim strip shown in FIG. 3 comprises an extrudable elongate moulding36, a printed and usually embossed foil member 42, and an overlay 40having radiused edges. The inlay (comprising the overlay 40 and the foilmember 42) is secured within moulding 36 by an adhesive layer 44. Thetrim strip 37 is secured to the vehicle body by adhesive layer 38 whichis protected with liner 40 which is removed at the time of installation.In contrast to the embodiments of FIG. 1, trim strip 37 is notnecessarily manufactured by casting plastic onto the inlay in theelongate moulding but can be formed by preparing a pre-cast trim stripas in FIG. 2 and laying this strip (minus release liner 34) into thechannel in moulding 36 where it is adhered with the adhesive 44. It willbe evident from this embodiment of the invention that it is notnecessary for the plastic overlay-forming material to be cast into placeand contact the side walls of the channel in the body moulding.

While the invention has been described in detail and by reference tospecific embodiments thereof, it will be apparent that numerousmodifications and variations are possible without departing from thescope of the appended claims.

What is claimed is:
 1. A process for forming a flexible trim stripsuitable for application to an automobile body, comprising:(a) forming aflexible elongate foil member having an upper surface and a lowersurface and having sharply defined peripheral edges but no upstandingsidewalls, (b) casting a fluent plastic composition onto said elongatefoil member while said foil member is retained in a substantially flatcondition free from surrounding side walls, such that said plastic flowsto the sharply defined peripheral edges of said foil member and forms apositive meniscus, (c) curing said plastic composition to form aflexible, weather-resistant clear plastic cap. (d) forming an elongageflexible moulding having an elongate channel in one surface thereof, (e)placing said foil member having said plastic cap thereon into saidchannel, and (f) securing said foil member in said channel via the lowersurface thereof.
 2. The process of claim 1 wherein said plastic is aflexible, abrasion-resistant polyurethane.
 3. The process of claim 1wherein said foil member is secured in said channel by providing thelower surface of said foil member with a layer of adhesive.
 4. A processfor forming a flexible trim strip, suitable for application to anautomobile body comprising:forming a flexible elongate member having anupper surface and a lower surface, and having sharply defined peripheraledges but no upstanding side walls, casting a fluent plastic compositiononto said elongate member while said elongate member is retained in asubstantially flat condition free from surrounding side walls, such thatsaid plastic flows to the sharply defined peripheral edges of saidelongate member and forms a positive meniscus, and curing said plasticcomposition to form a flexible, weather-resistant clear plastic cap toprovide a lens effect said elongate member and thereby opticallyenhancing the appearance of said upper surface of said elongate elongatemember as viewed through said clear plastic cap.
 5. The process of claim4 wherein said plastic cap is formed of a flexible, abrasion-resistantpolyurethane.
 6. The process of claim 4 wherein said lower surface ofsaid elongate member is provided with a layer of adhesive and anoverlying release film layer.
 7. The process of claim 6 furtherincluding the step of rolling said flexible trim strip up into a roll.8. The process of claim 4 wherein said clear plastic cap has a Shore Dhardness of about 45 to 65.